But since April 1, the centre has been operating a new parking system that requires people to enter their car registration number into a machine.

But many parking there say because the signage is so bad - they were unaware of the changes.

This week several people have been hit with £100 parking fines, though retired businessman Philip Derbyshire, 68, even claims to have entered his details and still got a fine...which he is now refusing to pay.

He said: “You don’t expect to go to the hospital for a proper appointment and get a parking ticket, it’s awful.

“It says on the ticket ‘do not ignore’.

“Well, that’s exactly what I intend to do.”

The NHS says the measures are to discourage non-patients using the car park and are not a money-making scheme.

On Monday, Coral Hamilton put her disabled badge in the front of her car and parked up at the medical centre as she usually would, totally unaware there was a new system in place.

Now she says she would rather “go to prison” than pay the parking fine.

She said; “The signs really are not clear - even with a magnifying glass you would struggle to read them.

“It’s just a money making scheme and I bet they have made thousands.”

The car park is operated by firm Smart Parking and the fines can be reduced to £60 if paid early.

But following the feedback, Northamptonshire Healthcare NHS Foundation Trust says it is going to review its signage at the Cliftonville Road health centre.

A spokeswoman said: “We have recently changed the car parking system at Highfield Clinical Care Centre at Northampton due to previous problems with the barrier system at the site.

“Our new system is based on number plate recognition and requires patients to enter their car registration details at the machine, otherwise they may be issued with a penalty notice.

“The aim of the system is to preserve parking spaces for our staff and patients and deter others from using it when they are not accessing our services.

“Unfortunately, some patients may have entered their details incorrectly or failed to supply them, leading to a fine notice. If they contact our PALS service on 0800 9178504 we will cancel the notice for them and would like to apologise for any inconvenience caused.

“We will also be improving our signage at the site to mitigate any further issues.”